RMM - Working at McMaster

McMaster University
Risk Management
Manual
RMM # 408
Title: Heat Stress Prevention Program
Date: February 2012
Page 2 of 7
acclimatization requires up to 3 weeks of continued physical activity under heat-stress
conditions.
4.8
Humidex – an index that combines the effects of temperatures and humidity to quantify
human discomfort due to perceived heat.
http://www.ccohs.ca/oshanswers/phys_agents/humidex.html
4.9
Relative Humidity – the moisture content of air expressed as a percent of the maximum
it can hold at a given temperature, (% RH). Optimum relative humidity for comfort is
between 30% to 60%.
4.10
Temperature – expressed in degrees Celsuis (ºC) or degrees Fahrenheit (ºF); optimum
temperature for comfort is 22 to 24ºC (72 to 75ºF). Temperature preferences vary
greatly among individuals.
4.11
WBGT – wet bulb globe temperature, an index used to quantify the true level of heat
stress on an individual from the combined effects of air temperature, humidity, air
movement, and radiant heat. The ACGIH “Work-Rest Regimen” table is based on wet
bulb globe temperatures.
4.12
Supervisor – Person who has charge of a workplace or authority over a worker.
4.13
Worker – A worker is a person who has entered into or is employed under a contract of
service or apprenticeship, written or oral, express or implied, manual labour or otherwise.
4.14
Acronyms
CJHSC – Central Joint Health and Safety Committee
EHS – Employee Health Services
EOHSS – Environmental and Occupational Health Support Services
FHSc safety office – Faculty of Health Sciences Safety Office
JHSC – Joint Health and Safety Committee
MOL – Ministry of Labour
OHCOW – Occupational Health Clinics for Ontario Workers
OHSA – Occupational Health and Safety Act
RMM – Risk Management Manual
RMSG – Risk Management Support Group
WSIB – Workplace Safety and Insurance Board
5
RESPONSIBILITIES
5.1
Role of Senior Managers (Deans / Directors / Chairs / Managers):
Senior Managers shall:
provide the required resources and direction to support the work in Heat Stress
Prevention Program and ensure issues are reviewed.
McMaster University
Risk Management
Manual
5.2
RMM # 408
Title: Heat Stress Prevention Program
Date: February 2012
Page 3 of 7
Role of Supervisors:
Supervisors shall:
exercise due diligence for personal safety when assigning work in extreme heat, and
shall ensure that all employees are familiar with first aid procedures for heat related
injuries or illnesses;
Follow the OHCOW Humidex Based Heat Response Plan (Appendix 1);
the ACGIH recommended „Work-Rest Regiments‟ (Appendix 2) shall be used as a
guideline when assigning work in extreme heat;
where applicable assign work in teams of two or more for personal safety in extreme
heat and humidity and, when appropriate, sun safety precautions concerning
Occupational Exposure to Sunlight (
http://www.ccohs.ca/oshanswers/diseases/skin_cancer.html#tphp ); and
ensure Injury/Incident Reports are filed with the EOHSS or FHSc safety office for all
heat related injuries and illnesses.
5.3
Role of Faculty, Staff , Students and Volunteers:
Individuals shall:
participate in the Heat Stress Prevention Program as identified by the Job Hazard
Analysis;
follow the best practice extreme heat guidelines for the work involved; and
report any heat related injuries or illnesses to the supervisor immediately.
Individuals may:
report extreme heat work concerns to the JHSC.
5.4
Role of Environmental and Occupational Health Support Services:
EOHSS shall:
when requested, provide resources for training on heat stress prevention; and
assist in investigations related to heat related injuries or illnesses.
5.5
Role of Faculty Health Science Safety Office (FHSc Safety Office):
Faculty Health Sciences Safety Office shall:
when requested, provide resources for training on heat stress prevention; and
assist in investigations related to heat related injuries or illnesses.
5.6
Role of Central Joint Health and Safety Committee (CJHSC):
The CJHSC shall:
review the Heat Stress Prevention Program on a regular basis.
McMaster University
Risk Management
Manual
5.7
RMM # 408
Title: Heat Stress Prevention Program
Date: February 2012
Page 4 of 7
Role of Joint Health and Safety Committees (JHSC):
JHSC‟s shall:
receive all incident reports related to heat related injuries and illnesses in the
workplace;
where required by the Act, participate in the investigation of a heat related injury or
illness; and
report all extreme heat conditions noted during routine workplace safety inspections;
and;
review SOPs on heat stress prevention.
6
EDUCATION AND AWARENESS
Following websites:
http://www.wsib.on.ca/files/Content/PreventionHSGuide/HeatStressGuide.pdf
http://www.ohcow.on.ca/menuweb/heat_stress_calculator.htm
http://news.ontario.ca/mol/en/2010/05/beat-the-heat.html
http://www.esao.on.ca/downloads/info_sheets/MOLHeatStress.pdf
http://www.ohcow.on.ca/menuweb/heat_stress_calculator.htm
7
RECORDS
7.1
EHS will retain copies of all injury/incident reports, and keep records of all WSIB claims
involving heat related injuries and illnesses or any other work related injury.
McMaster University
Risk Management
Manual
RMM # 408
Title: Heat Stress Prevention Program
Date: February 2012
Page 5 of 7
Humidex Based Heat Response Plan
What is it?
The Humidex plan is a simplified way of protecting workers from heat stress
which is based on the 2007 ACGIH Heat Stress TLV® (Threshold Limit
Value®) which uses wet bulb globe temperatures (WBGT) to estimate heat
strain. These WBGT’s were translated into Humidex.
The ACGIH specifies an action limit and a TLV® to prevent workers’ body
temperature from exceeding 38°C (38.5°C for acclimatized workers). Below
the action limit (Humidex 1 for work of moderate physical activity) most
workers will not experience heat stress. Most healthy, well-hydrated,
acclimatized workers not on medications will be able to tolerate heat stress
up to the TLV® (Humidex 2 for moderate physical activity). Between Humidex
1 and Humidex 2, general heat stress controls are needed and above
Humidex 2 job-specific controls are needed.
Note: in the translation process some simplifications and assumptions have
been made, therefore, the plan may not be applicable in all
circumstances and/or workplaces (follow steps #1-5 to ensure the
Humidex plan is appropriate for your workplace).
Humidex 1
Response
Humidex 2
25 – 29
supply water to workers on an “as needed” basis
32 – 35
30 – 33
post Heat Stress Alert notice;
encourage workers to drink extra water;
start recording hourly temperature and relative humidity
36 – 39
34 – 37
post Heat Stress Warning notice;
notify workers that they need to drink extra water;
ensure workers are trained to recognize symptoms
40 – 42
38 – 39
work with 15 minutes relief per hour can continue;
provide adequate cool (10-15 C ) water;
at least 1 cup (240 mL) of water every 20 minutes
worker with symptoms should seek medical attention
43 – 44
40 – 41
work with 30 minutes relief per hour can continue in
addition to the provisions listed previously;
45 – 46*
42 – 44
if feasible, work with 45 minutes relief per hour can
continue in addition to the provisions listed above.
47 – 49*
45
or over
only medically supervised work can continue
50*
or over
*at Humidex exposures above 45, heat stress should be managed as per
the ACGIH TLV®
McMaster University
Risk Management
Manual
RMM # 408
Title: Heat Stress Prevention Program
Date: February 2012
Page 6 of 7
Humidex 1, General Controls: General controls apply to unacclimatized workers and
include providing annual heat stress training, encouraging adequate fluid replacement,
permitting self-limitation of exposure, encouraging watching out for symptoms in coworkers, and adjusting expectations for workers coming back to work after an absence.
Workers doing moderate work are considered acclimatized in Ontario only if they
regularly work around heat sources (e.g. in foundries, around ovens, etc.). NOTE:
clothing and radiant heat must also be taken into account when using this guideline (see
steps #1-5 outlined on page 3).
Humidex 2, Job-Specific Controls: Job-specific controls include (in addition to general
controls) engineering controls to reduce physical job demands, shielding of radiant heat,
increased air movement, reduction of heat and moisture emissions at the source,
adjusting exposure times to allow sufficient recovery, and personal protective equipment
that provides for body cooling
McMaster University
Risk Management
Manual
RMM # 408
Title: Heat Stress Prevention Program
Date: February 2012
Page 7 of 7
Appendix 2
Heat Stress Guidelines and References
Recommended Work-Rest Regimens for Outdoor Work
All temperatures are in units of wet bulb globe temperature (WBGT) degrees Celsius. The
recommendations are designed to prevent the core body temperatures of fit, acclimatized
workers from rising above 38 ⁰C.
Screen Criteria for TLV and Action Limit for Heat Stress Exposure
TLV® (WBGT values in °C)
Action Limit (WBGT values in °C)
Allocation
of Work in
a Cycle of
Work and
Recovery
75 to 100%
50 to 75%
25 to 50%
0 to 25%
Light
Moderate
Heavy
31.0
31.0
32.0
32.5
28.0
29.0
30.0
31.5
-27.5
29.0
30.5
Very
Heavy
--28.0
30.0
Light
Moderate
Heavy
28.0
28.5
29.5
30.0
25.0
26.0
27.0
29.0
-24.0
25.5
28.0
Very
Heavy
--24.5
27.0
Recommendations for Work in Hot Environments
Wear light-coloured clothing for working outside to allow free air movement and sweat
evaporation.
Increase the frequency and length of rest breaks.
Schedule hot jobs at cooler times of the day.
Provide cool drinking water and consume a cup every 20 minutes or so.
Make sure everyone is properly acclimatized.
Recognize the signs and symptoms of heat stress and use a “buddy system” since people are
not likely to notice their own symptoms.
ACGIH – Heat Stress Tables http://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_4.html#iii:4_3
OHCOW Humidex calculator: http://www.ohcow.on.ca/menuweb/heat_stress_calculator.htm